ND filters

[darb]

planning to get some fairly strong ND filters ... most importantly a gradual

in reading some online information im a little confused whether to go hard step or soft step, they have cited that the CCD size will affect how effective a gradual filter is.

such as ;

When working with Graduated ND Filters, you will be using only the central 2/3 of the total filter area. The graduated density area--starting from the clear lower half of the filter up to the area of fullest neutral density--will span a relatively larger area of your final image than it would if you're using a 35-mm film camera. This difference changes the visual effect of a hard step filter to a much more gradual transition.


Anyone recommend a decent 3-fstop gradual ND to use ?

As for a full frame ND (i also want.) ... I was looking at thsi sucker ;

http://www.singh-ray.com/varind.html Variable full frame (from 1 to 8 fstops, full frame.)

what do you lot think?

im having most trouble deciding on whether i needa hard graduation or soft graduation on the GND ... probably hoya or something like that.

[Onyx]

Darb - you can simulate the effect of a grad ND with digital, by bracketting and combining the images in photoshop.
Actually, you might not even need multiple frames, as you can, withiin limits, pull quite a fair bit of detail from shadows.

During the last Sydnet meet, MattK demonstrated this, and perhaps he'll explain in further details. It basically entails creating a duplicate layer, desaturated and inverted so you have a negative image. Apply a slight gaussian blur to this negative, and overlay it on top of the original.

http://www.luminous-landscape.com/tutor ... ures.shtml

I have a straight ND for waterfall use (to combat the ISO200 minimum on the D70), but have read that for a grad ND - it's best to get one as a removable filter system (eg. cokin) instead of a screw on lens type, as it increases shooting flexibility. With a screw on type, you're basically restricted to having the soft or hard edge in the middle, and that may limit the types of images you're able to take. It may also wreck havoc on lenses with front elements that rotate on focusing or zooming (much like CPL).

[darb]

thanks onyx ... i always try to reduce my post processing so im happy with getting a cuople of filters.

thus far ive found the following information on what im thinking on ;

with the tabacco filter, i presume i can do this easily enough with a photoshop action so i probably wont bother.

with regard to the Full ND ... would a polariser effectively be doing the job of this ND (even when youre not in polarised light etc.)? Or is the pl-circ only somewhat effective (afternoon shots in flowing streams, etc.) ... I ask because i already have and use a circ polariser, and it is usually quite effective in slowing me down.

All Hoya,

67mm filters ;

Half NDx4 (gradual.)
http://www.thkphoto.com/products/hoya/oef-08.html

NDx8 (full ND)
http://www.thkphoto.com/products/hoya/oef-05.html

Star Six
http://www.thkphoto.com/products/hoya/oef-03.html

62mm Filter ;

Tabacco Gradual Colour. (could be achieved with a photoshop action?)
http://www.thkphoto.com/products/hoya/cef-07.html

id really like ;

http://www.singh-ray.com/varind.html

but unsure wehre i can get it.

[Onyx]

Some of the cheaper CPLs can lose up to 2 stops of light (better ones 1.5 or 1 1/3 stops) but in this case I suppose losing the stops is beneficial, and it can be used as an ND substitute. I did try out a Tiffen CPL vs. ND4 at Adorama, and both gave the same spot metered exposures indoors (consistent 2 stops less than filterless on the D70 with kit lens).

All those Hoya's you linked to are screw on types, so you'll be stuck with the boundary in the middle of the frame. This may or may not be acceptable or useful to you. The singh-ray is IMHO quite costly, and hasn't been met with good user reviews at Nikonians forums. But then they're a fussy bunch. I can see it being much more handy than carrying several NDs within its range - and combined with your apparent love of long exposure photography, I believe it may suit you quite well. However, the cheap arse in me - I suspect the effect can also be achieved with 2 linear polarisers (when lined up perpendicular, it'll effectively block out ALL light).

[dooda]

I just bought the cokin system with ND Graduated and really like it. I strongly recommend not going with the threaded lens. Go to a camera store and check on out and see how it works. The only trouble in my opinion is the storing of it; sliding in filter after filter is dreamy though.

I'm with you Darb, I prefer spending a little more time behind the camera if it means less time in Photoshop. Photoshop is like eating healthy food and excersize; the result is great but the process sucks.

[darb]

the main issue i have mate is that i need it to be very compact. with a 67mm front element, i presume the square cokin adapter and filters are really quite huge?

i dont mind being forced into the middle so to speak,, for now anyway, if it really bugs me thjen ill get the cokin set, this is basically just for me to start playing and testing with it. (thought theyre not so cheap.)

ps the camera stores dont have any range whatsoever. so its basically between those 3 different screwin filters to choose from.

how much is the cokin set worth?

[dooda]

In Canadian Money, which is about 83 cents to the American (and sounds like it is about on par with the Australian) I paid about 75.00. I ended up getting a ND graduated, the filter holder, the ring, and a little book. Your local store should have one around that you can look at and see if it's too big. So far the quality has been pretty good, (although I've never seen a real difference in quality with filters).

When I said strongly recommend not going with threaded lens, I meant threaded filters, mostly the graduated neutral density because you can slide it up and down and the cokin also slides around in a circle for better manipulation. The NDGrad was what got me into the cokin.